Novel Manifestation of Retinal Hemangioblastomas Detected by Optical Coherence Tomography Angiography in von Hippel-Lindau Disease

Published:February 10, 2023 DOI:https://doi.org/10.1016/j.ophtha.2023.02.008

Purpose
To elucidate the clinical characteristics of atypical retinal vascular proliferation in patients with von Hippel-Lindau (VHL) disease using optical coherence tomography angiography (OCTA).

Design
Prospective observational study.
Participants
Fifty-seven consecutive patients diagnosed with VHL disease who visited Kyoto University Hospital between January 2019 and March 2022.

Methods
Retinal hemangioblastomas (RHs) were assessed using multimodal imaging including OCTA. RHs were classified into two phenotypes: nodular and flat types. Nodular-type RHs were defined as typical RHs that were globular, well-circumscribed tumors, often accompanied with dilated feeder arterioles and draining venules. Flat-type RHs lacked a protruded red or colored mass, had variable and indistinct borders, and were not accompanied with feeder and draining vessels.
Main outcome measures
The prevalence, distribution, and description of atypical flat RHs.

Results
Among 57 consecutive patients with VHL disease, 37 patients (64.9%) showed RHs in at least 1 eye. Bilateral RHs were seen in 23 patients (62.2%). Among 58 eyes of 37 patients with RHs, typical nodular-type RHs were detected in 54 eyes. Nodular-type RHs were seen mainly in the peripheral retina and occasionally in the peripapillary region, and they showed exudative changes in some cases. Flat-type RHs were detected in 7 eyes (12.1%). Four eyes showed only flat-type RHs, and 3 eyes showed both types in the same eye. Most flat-type RHs appeared as retinal hemorrhage or faint flat abnormal retinal vessels in the inner retina on the fundus examination, often within the macula area or peripapillary. In all eyes with flat-type RHs, OCTA showed abundant blood flow in the lesions. OCT revealed that flat-type RHs were seen mainly between the retinal nerve fiber layer and the ganglion cell layer, and occasionally within the inner nuclear layer. During a mean follow-up period of 20.4 ± ۱۵.۰ months, no flat-type RHs accompanied exudative change or tractional retinal detachment, or progression in size.

Conclusions
Patients with VHL disease can present with two distinct types of RHs; the classic nodular-type and atypical flat-type RHs. OCTA can be useful in improving the detection of atypical flat-type RHs which can be difficult to detect clinically.

۱-In the current study, 37 (64.9%) of 57 consecutive VHL patients presented with RHs in at least 1 eye. This rate is slightly higher than that in previous reports (25–۶۰%)

۲-flat-type RHs were observed in 7 (12.1%) of 58 eyes with VHL-related RHs
۳- All the typical nodular-type RHs were observed peripherally or peripapillary. Flat-type RHs were observed mainly peripapillary or within the macula region

۳-the lesions were completely undetectable during the fundus examination, but OCTA was very sensitive to detecting this type of RH

۴-In 1 eye (case 4), OCTA clearly revealed a subtle flat-type lesion that even FA could not detect

Flat-type RHs sometimes appear as reddish flat lesions that look like a retinal hemorrhage in the macula area (case 3). However, OCTA findings indicated that these reddish lesions were actually atypical RHs with abundant blood flow. OCTA was very effective in detecting flat-type RHs within the macula region or around the optic disc.

Furthermore, because OCTA imaging is easily performed in the posterior pole where flat-type RHs frequently occur, OCTA should be valuable for screening the fundus of VHL patients.

Typical nodular-type RHs located above the RNFL protruded towards the vitreous cavity (Case 1). In contrast, flat-type RHs, located in various layers of the inner layers, remained flat and never protruded into the vitreous cavity. Detailed OCT analysis revealed that flat-type RHs were mainly seen between the RNFL and the GCL (Case 3, 5), and occasionally within the INL (Case 2)

Based on the OCT and OCTA evaluations, flat-type RHs associated with VHL mainly developed from the superficial capillary plexus of the retina, and occasionally from the deep capillary plexus of the retina.

No eyes with flat-type RHs showed exudative change during the follow-up, and all eyes maintained visual acuity.

They accompanied no exudation or tractional retinal detachment.no growth